The Collaborative International Dictionary of English v.0.48:

Nerve \Nerve\ (n[~e]rv), v. t. [imp. & p. p. Nerved
   (n[~e]rvs); p. pr. & vb. n. Nerving.]
   To give strength or vigor to; to supply with force; as, fear
   nerved his arm.
   [1913 Webster]